====== Weibull Fitting ======

Fitting performed by Bill Rowe.

Weibull parameters would be as follows:
 
Outputs:\\
Saturated cross section 5.1 E-7 cm2\\
Width: 15.6\\
Exponent: 2.2\\
Threshold: 0.21\\
 
Inputs (all data considered):\\
Saturated cross section 1.5 E-7 cm2\\
Width: 18.4\\
Exponent: 3.1\\
Threshold: 0.1\\
 
Note, because the data point at an LET of 10 seems low, this really doesn’t fit the data well. Omitting the data point at an LET of 10 gives the following:\\
Saturated cross section 7.2E-8 cm2\
Width: 9.6\\
Exponent: 1.6\\
Threshold: 0.3\\
 
A plot with this parameters passes through the data points at LET of .6, 6.2 and 15 and bounds the data point at a LET of 1.1. So, these are likely better estimates of the Weibull parameters than what is obtained as a best fit with all of the data.
 
Summing inputs and outputs the Weibull parameters become:\\
Saturated cross section 9.5 E-7 cm2\\
Width: 21.7\\
Exponent: 2.1\\
Threshold: 0.014\\
 
The problem of the low cross section for inputs at an LET of 10 disappears because the output cross section doesn’t show the same problem and the output cross section is more than an order of magnitude larger than the input cross section at a LET of 10.
 
Comparing the above, things look reasonable in that the saturated cross section increases for combination, both the width and exponent look similar to the output case and the threshold takes on the smaller input cross section threshold.